Ignition coil



Feb. 17, 1931. w. A. CHRQ'YST ET AL 1,792,730

IGNITION COIL Filed Nov. 29, 1927' Patented Feb. 17, 1931 UNITED STATESPATENT OFFICE WILLIAM A. CHBYST, OF DAYTON, OHIO, AND RALPH I. BATES, OIANDERSON, IN- DIANA, ASSIGNORS TO DELCO-BCEMY CORPORATION, OF DAYTON,OHIO, A CORPO- BATION OF DELAWARE IGNITION COIL Application filedNovember 29, 1927. .Serial No. 286,552.

This invention relates to improvements in the manufacture of ignitioncoils particularly for automobiles and includes among its.

objects the provision of improved means for supporting the coilwindingsand magnetic structure within the case and for providing adequateinsulation for the secondary winding. A further object is to provide forthe ready passage of a sealing compoundsuch as hydrolene to the bottomof the ignition coil case when said sealing compound is poured in afterthe parts ,of the ignition coil ave been assenibled within the case.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of one form of the presentinvention is clearly shown.

In the drawings:

Fi 1, is a plan-view of the coils embodyin t e present-invention.

ig. 2 is an underside view of the coil case cover.

Fig. 3 is a fragmentary plan view of a portion of the material used inthe external magnetic circuit.

Fig. 4 is a sectional view on the line 4-4 of Fig. 3. I

Fig. 5 is a longitudinal sectional view of the coil taken on the line 55of F ig. 1.

The coil housing comprises a tubu ar case 20 closed at the bottom by adisc 21 joined to the case by a seam 22 which may be soldered. The case20 is provided at its upper edge with an annular bead 23' for a purposeto be described. The case 20 is welded to a mounting bracket 24 havingapertured cars 25.

A non-conducting fiberdisc placed upon the bottom of the containerorupon the upper surface of the disc 21 and is coated with insulatingvarnish such as shellac. An insulat ing block 27 preferably of glass isplaced u n the disc 26 while the varnish is still wet.

bed set the varnish tends to hold the insulator 27 in position. i Theinsulator 27 proupon anon-conducting tube 31 and covered:

with a wrapping of several turns of insulating paper 32. The tube 31receives the center core of the magnetic circuit of the coil whichcomprises a bundle of iron wires 33 projecting above the upper end ofthe tube 31 and terminating slightly short of the lower end of the tubeto provide a space within the tube for receiving a fiber plug 34. Theinner end lead 35 of the secondary winding 30 is grounded upon the core33. The outside lead 36 is brought out through a suitable opening in thewrappin 31.

Before assem ling the secondary and' center core assembly within thecontainer as shown there is placed within the case 20 a primary winding40 which has beenwound upon a non-conducting tube 41 having its insidediameter a little larger than the outside diameter of the wrapping 32 ofthe secondary coil 30. The lower edge of the tube 41 will be receivedwithin the recess 28 in the block 27. .Near its lower edge the tube 41-is provided with side openings 42 for a purpose to be described. A tubeabout which the external magnetic struc-- 54 which are locatedalternately in different planes as shown in Fig. 4 so that no twoadacent strips will occupy the same plane. This formation interrupts theeddy current circuits. The material 52 is placed upon a strip of paperinsulation 55, and both strips 52 and 55 are wound together upon thenonconducting tube 50. The external magnetic circuit assembly may beplaced in the container after the primary assembly has been placedtherein; or the external magnetic circuit assembly may be placed aroundthe rimary assembly and both these assemb ies placed together within thecase. The wall of the. recess 28 tends to hold the tubes 41 and 32 inconcentric relation so that there will be an annular space between them.

Before placing the secondary and center core assembly in the case withinthe primary assembly, the assembled. ease, external magnetic circuitassembly and the primary assembly are heated to a temperature of about300 degrees Fahr. or to a point a little below the temperature of themelted sealing com pound such as hydrolene. While the assembly is stillapproximately at this temperature, a small quantity of melted sealingcompound is poured into the case so that at least the recess 28 in theglass. block 27 is completely the holes 42 into the voids below theprimary coil 40 as indicated b the portion covered by the small dots 80.he secondary and center core assembly may be warmed, but not suficientlyto melt the impregnating wax, before placing this assembly within thecase.

The wire 43 leading from the inside turn of the primary 40 is locatednear the outside lead .36 of the secondarv. The outside lead 44 of therimar 40 is located diametricallyoppositet einsi elead.

The cover for the container comprises a body 60 of molded insulatingmaterial which is provided with an insert in the form of a sheet metalring 61 adapted to telescopically engage the upper end of the can 20.Other inserts are the terminal plates 62 and 63 which receive screws 64for attaching terminal clips 65. The body 60 is provided centrally withan insulated cable receiving socket 66 which is lined with a conductingsleeve 72 provided as an insert. Before attaching the cover 60 tothecase 20, the wires 36 and 43 are passed through a hole 68 leadingthrough the plate 63 and the wire 44 is passed through a hole 69 leadingto the, plate 62. Then melted sealing compound, such as hydrolenerepresented by the portions covered by small dots 80, is poured while ina fluid state upon the assemblies within the case 20. Some of thismaterial will pass between the primary and secondary assemblies throughthe space between the wrapping 32 and the tube 41. Before the sealingcompound has solidified. the cover 60 is assembled as shown and its longskirt or flange 70 will enter this sealing material above the primaryassembly and will cause some of it to be forced into the spaces betweenthe cover 60 and the coil assemblies at the top of the case. Thus theskirt 70 serves to spread the sealing compound to cause it to be moreeffective' in providing a firmanchorage for the coil assemblies, andalso serves more weave elfectively to insulate the inside lead 35' ofthe secondary from the outside lead 36 which is forced to take aposition exterior to the skirt 70.

Following the operation of assembling the cover 60 upon the case 20,thelead wires are attached by soldering to respective terminal plates 62and 63. A nail 71 is driven through a previously formed hole in the body60 and socket lining member 72 so asto make an electrical connectionbetween the member 72 and the core 33 upon which the inside lead 35 ofthe secondary is grounded. Then the cover 60 is permanently joined tothe case 20 by soldering between the head 23 and the ring 61. Aconducting plug 73 is driven through the socket lining 72 to hold thenail 71 permanently in position and to aid in excluding moisture fromthe interior or the case. The coil is then ready for painting andinspection.

While the form of embodiment of the present invention as hereindisclosed, constitutes a preferred form. it is to be understood that.

other forms might be adopted, all coming within the scope of the claimswhich follow.

What is claimed is as follows:

1. An ignition coil comprising, in combination, a tubular case,insulating bodies located adjacent each end of the case, one of theinsulating bodies providing a cover for the case and carrying terminalsfor the windings and provided with a depending annular skirt whichsurrounds the upper end of the secondary assembly, the skirt serving tospread a filler of insulating compound which is poured While in a fluidstate upon the wind ings in the case, and the skirt serving to insulatethe secondary leads from each other.

2. An ignition coil comprising, in combination, a tubular case,insulating bodies located adjacent each end of the case one of theinsulating bodies provides a cover for the case and carries terminalsfor the windings and is provided with an annular metal flange adapted totelescopically engage one end of the case and tobe joined thereto, saidcover having an annular, depending skirt concentric with the metalflange and defining a recess for receiving the upper end of'thesecondary assembly, said skirt serving to insulate the secondary leadsfrom each other.

3. An ignition coil comprising, primary and secondary windings woundupon separate tubes, a tubular case, and insulating members locatedadjacent the ends of the case and having provisions for receiving endportions of one of the windings and the tubes in order to hold thewindings in concentric relation one within the other with an annularspace between them, said annular space providing a passage for a sealingcompound which is pouredwhile in a fluid state upon the upper end of thewindings after being assembled within the case.

'4. An ignition coil accordin to claim 3 in which the tube upon which 1;e primary is wound surrounds the secondary and extends below the primaryturns and is provided with side openings to permit the passage ofsealing compound into the space below the primary turns.

5. The method of making an ignition coil having separatelyformedwindings one adapted to be located within the other, whichcomprises placing the outer winding within a case, heating the case andouter winding, pouring upon the bottom of the case a quantity of meltedsealing compound, and then forcing the inner winding through the outerwinding and the melted compound in the bottom of the case before thecompound solidifies.

6. An ignition coil comprising, in combination, a tubular case,insulating members located adjacent each end of the case and providedwith facing, aligned recesses, an assembly comprising a secondarywinding and a central core confined between said insulators, the ends ofthe assembly being received by said recesses, and a primary winding upona nonconducting tube surrounding and spaced from the secondary winding,said tube being received by the recess of one of said insulatingmembers.

7. An ignition coil according to claim 6 in which the said insulatingmembers maintain the windings in their spaced concentric relation.

8. An ignition coil according to claim 6 in which one of the insulatingmembers has provisions for receiving an end of the assembly embodying anannular skirt surrounding and positioning one end of the secondarywinding with respect to the primary winding.

9. An ignition coil comprising, in combination, a tubular case,insulating members located adjacent each end of the case and providedwith facing, aligned recesses, a bottom disc between one of saidinsulators and an end closure of said case, the other insulating memberproviding a cover for the other end of said case, a winding assemblyconfined between and rigidly supported by said insulators, the endportions of said amembly being disposed within the recesses of saidinsulators.

10. An ignition coil comprising, in combination, primary andsecondarywindings located concentrically around a central core, an externalmagnetizable body comprising an oblong strip of sheet iron slittransversely and wrapped together with a strip of insulating paper intoa tube which surrounds the windings, and a tubular case enclosing thewindings and magnetizable bodies, sai case supporting a skirtedinsulating member against an end closure thereof, and a skirted coverfor said case, said cover and insulating member providing alignedopposing recesses signatures.

WILLIAM A. GHRYST.

RALPH I. BATES.

